[Esa-l]Re: Sircam virus filter

John D. Hardin jhardin at impsec.org
Wed Aug 1 20:43:37 PDT 2001


On Wed, 1 Aug 2001, Juan Manuel Calvo wrote:

> I have found a very simple solution to the Sircam problem. Your
> procmail sanitizer allows defang the attachment but the users
> receives the email.

Not if you poison *.bat *.pif *.lnk and *.com - is there really any
reason to be accepting these sort of attachments from random people
out on the Internet?

> I have added the following lines in my /etc/procmailrc BEFORE
> the sanitizer:
> 
> ------------cut here-----------------------
> # This tries to match a binary string from the SirCam virus
> # in the base64 encoded MIME attachment.
> # B: search body, D case sensitive
> :0BD
> *
> AAAAGgU0NhbTMyABCDTUlN|AAAAAaBTQ2FtMzIAEINNSU1F|ABkAAAABoFNDYW0zMgAQg01J
> /var/spool/mail/sircamvirus

That's a signature-based defense. What if SirCam mutates a little?

--
 John Hardin KA7OHZ   ICQ#15735746   http://www.wolfenet.com/~jhardin/
 jhardin at impsec.org        pgpk -a finger://gonzo.wolfenet.com/jhardin
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